Tuning microstructure and improving the corrosion resistance of a Ti-6Al-3Nb-2Zr-1Mo alloy via solution and aging treatments

Herein, the influences of solution-aging treatments on the corrosion behaviors of a wrought Ti-6Al-3Nb-2Zr-1Mo alloy are investigated. The solution-aging treated alloys exhibit a better corrosion performance than the wrought alloy, stemming from the alleviated galvanic corrosion. In artificial seawater, all alloys display a spontaneous passivation behavior, and the oxygen reduction reaction (ORR), affected by diffusion and charge-transfer pro-cesses, performs as the prominent cathodic reaction. However, in 5 M HCl, the activation-passivation transition occurs, and the cathodic reaction is mainly related to the hydrogen evolution reaction (HER) controlled by the Volmer reaction. Furthermore, we illustrate the relevant ORR and HER mechanisms.